In the lid panel and the like of the luggage compartment in an automobile such as the floor panel and the luggage board, the panel in which the cover material such as the non-woven fabric is laminated to the panel surface is used in order to improve touch sense of the panel surface and to impart a design effect (see Japanese Patent Laid-Open No. H1-347720 and Japanese Patent Laid-Open No. 2000-289095). However, recently utilization of the luggage compartment and the like of the automobile is diversified, accordingly demands for the panel formed by the integrally welded resin sheet in which the three-dimensional pattern such as a grain pattern is formed and the like are grown besides the conventional panel in which the non-woven fabric is laminated.
For example, Japanese Patent Laid-Open No. H9-39078 discloses one in which a decorative fabric having a three-layer structure of the cover material, a foam, and a fabric sheet, integrally laminated to a surface wall of a upholstered hollow molding component (panel) while blow molding and the fabric sheet is the non-woven fabric whose weight per area ranges from 50 to 250 g/m2. Japanese Patent Laid-Open No. H9-39079 discloses one in which the cover material, which is formed by the bonding of a resin sheet and a fabric sheet, is integrally laminated to the surface wall of the upholstered hollow molding component (panel) while blow molding and the resin sheet is made of polypropylene or PET whose tensile modulus ranges from 3000 to 12000 kg/cm2.
Japanese Patent Laid-Open No. S62-25117 discloses a molding method, in which a coating layer (cover material) is heated and integrally laminated while blow molding, the cover material is formed by bonding a non-woven fabric to a soft PVC, and a not-flat pattern of a mold is transferred. Japanese Patent Laid-Open No. H10-235720 discloses a panel with skin, to which a fabric having fuzzy hairs (non-woven fabric) is integrally laminated, used for a vehicle cargo floor panel and the like, and the panel with skin has an double-walled rib. Japanese Patent Laid-Open No. 2001-277342 and Japanese Patent Laid-Open No. 2004-74660 disclose that a part of a parison is compressed and thinned to form a hinge portion having a groove while blow molding and the non-woven fabric is placed between the cover material and the parison from the viewpoint of improving cover material bonding strength.
In the panel with skin produced by the blow molding is formed by integrally laminating a cover material to a melted parison while molding. In the case where the resin sheet having no air permeability is used as the cover material, there is a problem that air remains between the resin sheet and parison arranged in the mold. In order to prevent the above problem, usually a resin sheet in which the foam or the non-woven fabric is placed is used.
In the vehicle interior panel and the like, it is desired that the not-flat three-dimensional pattern such as the fine grain pattern or a regular embossing pattern emerges on the outer surface of the cover material. However, when the blow molding is performed with a resin sheet having a not-flat three-dimensional pattern, the not-flat three-dimensional pattern becomes flat by pressure while blow molding and heat from the parison, which results in deformation of the resin sheet. Further, particularly in an end portion of the resin sheet, the not-flat three-dimensional pattern is largely elongated by stretch of the resin sheet, and appearance is remarkably detracted.
A not-flat three-dimensional pattern along the cavity of the mold can be transferred as a method of causing the not-flat three-dimensional pattern to appear on the outer surface of the cover material. However, the resin sheet, in which the foam or the non-woven fabric is placed, is usually thick, three-dimensional pattern along the cavity of the mold cannot be transferred sufficiently. Particularly, in the case where the resin sheet is not previously softened by heating from the viewpoint of moldability, there is problem that the three-dimensional pattern having the good appearance cannot be reproduced.
In the vehicle interior panel, a rib, which is protruded from a backside wall and integrally welded to the backside of the surface wall, is formed in order to enhance rigidity of a hollow double-walled structure, or a thin hinge portion, in which the surface wall and the backside wall are integrally welded, is formed in order to partially open and close divided floor boxes when the vehicle interior panel is used as a lid of the floor box. In this case, because the rib or the hinge portion is formed by integrally welding the surface wall and the backside wall, sink marks and unevenness of the transfer ability are generated in the three-dimensional pattern appearing on the surface of the resin sheet by a difference of molding condition between the welded portion and a portion corresponding to a hollow space where the surface wall and the backside wall are not welded. As a result, because the transfer is partially insufficient, there is the problem that the appearance is detracted by becoming dim or flatting of the three-dimensional pattern.
In the panel with skin produced by the blow molding, there is a problem that peeling of the cover material is easy to occur at the end of the sheet and the hinge portion. Therefore, in order to prevent the peeling and uplift of the cover material, it is necessary to take such countermeasures such as molding the cover material integrally by winding the end of the cover material in the backside of the panel with a slide mold, and forming a wide recess from the cover material side in the hinge portion to broaden a bonding area.